With the proliferation of wireless handheld devices and the data handling capability of these devices, the bandwidth required to support their use has continuously increased over the last decade. As more personal data is being communicated with wireless devices, privacy is an ever increasing concern. Moreover, some environments are inhospitable to radio frequency wireless communications such as underwater communications. In these environments, high data rates may not be supportable using radio frequency or acoustic communications. Optical communications may provide solutions to these problems.
Light emitting diodes (LEDs) and organic light emitting diodes (OLEDs) directly convert electronically modulated signals into optically modulated signals and play essential role in short-haul optical wireless communication links. Improving the modulation speed and the quantum efficiency of LEDs have been roadblocks to achieving better optical wireless communications systems. In the past, photonic crystals and roughened surfaces have been used to increase both the brightness and the modulation speed of LEDs.